Appain Upgrade 18.1

DS deployment might fail due to a variety of issues (DB unavailable, bad credentials, bad configuration, etc.). There should be an error message in the application server log that should provide details on why you get this failure.

If it was an upgrade, I would make sure all the appropriate drivers, custom.properties updates, etc. are merged correctly.

Can you attach the server.log from <JBOSS_HOME>\standalone\log?.

Is it failing all the time? Based on that we can find a solution for your issue

I have met this situation before but not particularly for 18.1.
What I do is to stop Appian , data server, search server and engines; then restart them again.
Then it deployed successfully afterwards.

You may try and see if the error persist.

It's failing all the time but Appian works fine

I tried but failing

Data source mismatch ! Kindly verify the JNDI Names.

Mostly the Database connection is not successful, just have a look at it.